SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f1246680712b1ef8e55006f0c86cae5a763521aff65ad0eb6e2754a6669fbd6' 
  AND token = 'IwiahvY8Rb0rLnNroFyI0/c2hASALlHHq9Jcr7YRp8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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