SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa02c95421d7bfc7cb5a997344a99fdf34c929a04d269011e76cd5cfdee820c5' 
  AND token = 'AfGp9BW+Ro9j5dSLPBoj4ZtVJ8M1HmbFfI2trKlVJN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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