SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bced5db9802dcae5e952dda8986f636067c91993cd47a70591afd4aa721bfdb' 
  AND token = 'EtKFyv2xYrSWbCgGJ/5QurMRakdHtvsRf5ZgB5rGivc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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