SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abba5a31dff2faacb2bd14006a5776126ab9b1996307587b6a60279bc557a655' 
  AND token = 'wQR2aHBzER5GnXJafvp14BkfQvlv6buG5GXw2lX/DIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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