Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa84733f53374557db6aa3d3b8e3a945a2de2b9f4d0dae2c56a94741ab56bf2c' 
  AND token = 'n23ZVllrTk+VCNATqp1v9f4qlFbmbdZ1gKy3ZuFEPCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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