SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54b181ce5170294b580a4a0a398915ca3f3be257606aadfe829fd1bedb0d3284' 
  AND token = 'rEI1SUqMd5dTCQ+ImiRioAIHtU65Bl0ZCkgVSx6lXE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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