SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e539fe47bc5a918c0ad7716c22cdc32ada4f44d49e205b9452230f2422c71cc' 
  AND token = '7lXfWjqusn9+hRhUJ02MY3ViPspCP9ubnqxn5CLj3iQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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