SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9136f44452eab784c94a621abc8be666bebe788a0f6be8d5de5a6b0a11154b3c' 
  AND token = 'T61wafDrE6pktsnbrLkYq6M/YDYDpeOMwQhbs8V7oEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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