Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8553b39db11c5b83b96799f70f38c537a11abe3cc2f970147b1a78a9f95cbaf8' 
  AND token = 'NBDKJq8oSas0Kj+1Z2dEqSx7cZ90Mj8VhFJfe34Vjrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}