SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34463ac4f2947593529e08face857784a4e381addef7cb2b1b938725e8f27219' 
  AND token = 'esDTkjzYKWAENBKtdw7BZv8vCMmuUwqKqbjYuk7RylI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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