SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '249b30852eb52186af986c2f5b9dc32cce43780915da5b93fd19d64f72bf5913' 
  AND token = 'QFUGBhKZQ3srAqqfusEnTAvb13/7o3xexnJizbSBOrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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