SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f86732cbbaaca7ea621e955d37fbe82b42fd82d1539ebbedc6a8bb47fc535de1' 
  AND token = 'JVqK4cnM9uAou4tWmOhjnzJo1P58asKyD563tfiMDOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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