SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fbcdd99f40f030b0c4a252c91acd64262e8897f93f34a5dd31213f6846fabc0' 
  AND token = '+xkFFARMJ3+9KhmgKMwZRObk1RChlHfOTwHVxYO1+Ws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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