SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97535deb330f1fe63768c79c438dcb29d60c2149b1ddd6196d49b373bafdd549' 
  AND token = 'U/9eZCKy5u5z+TjTwe6GbaPBYEU/hFIkWH/nJUOTs9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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