SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65b52b884baf7f696d42adf389429c1db2398d9ce994258b82b1533691ffbc39' 
  AND token = 'c0TXIVx7FsQL7NbAuKdF+FAD11OUDFfKkPHHK1IrDOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}