SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81c3c4ae6a09105e56e16d8fbf245de6a15d4773aec7ba6db9933b4d2843ad88' 
  AND token = 'buE7G901YSBNMiPRXdqzaCDdiUswVsx/IKjoWzeOJrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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