SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cda077b9adca3a37150319928afd956d8e7762362ebafe171ffa2624a381b67' 
  AND token = '6fOsaqPOs5SUfvryUwXuu98GjM06Tfgtuox/6LfcvhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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