SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23a13aa46710b7fcdfa169a89d78d5397e6963ee47da0061754a0fce1fad091d' 
  AND token = 'tAw2VkxnMBRti+TSc2jCsqljgEpPY38XZFGjHVT6kl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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