SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd78ccaa8a65a2c6bd82e0d49356c71da238f0acee7006407782cd6e9d7839196' 
  AND token = '937bJwYX6sNskm8J3p0OO1C0JESrHcOGSbYtloVTgQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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