SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c347c6d0a9e4d81fe9015efde66ff6c082b8786c37252b739d78c6384e50cfa1' 
  AND token = 'NB/vopLWCk9eU8hDNKxXuJ/m3jqI6HVSdeGNRH9FaC4=' 
  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"
    }
  }
}