SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '53914867e9e996c48fc699f803144a0dc3675cb87737b94db620bc5ec9434bfe' 
  AND token = '+V1d5W2Aju7C9vG48pR4h59kk2+X4cYChKoJ5k3SyM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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