SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99cf9db2f360082409d0a49a00245f93fdb88c6e109da4a5b2cac9beacc3e05f' 
  AND token = 'I03tHJ6u4XhnpJCwUlsL4IuPo4ZRWVHflF4M4u6nQm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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