SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b69efe4a23c65624400aed785b50842a3b9ba2a7a914b1da151129c3f77d76de' 
  AND token = 'fKMsB0D+RlgzK/6T67wmt65VVOjZfniQtX8ZKfkb7bQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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