SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '135e8ff34eeb46e2784f75f27c5353836a9dde5ce79b454ccd12599d6dfa00b3' 
  AND token = 'lEOTzaA1HL8rhgekq448gmKokrrQSEqziqerCIdQnZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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