SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5743166e19ee9b04c3d7a379667dda650ca74271780fa45e038682c48e73ff17' 
  AND token = 'TwJHy0/ZDhpj9gdz9OxQy3gPmFRdGVunxNA+W8Ufo3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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