SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66ec4e851213a26400ddf1e9b42cca0398c40dbd9d7ac42bb4ad5f12349f47ce' 
  AND token = 'y5xLA0WLCo46CrFsDarITeckz44Z2EgDdo++Y2JM5yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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