SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88f2abd391ca52777cabd2e375052bcb1f5862887b66b509d060a59d08965d8a' 
  AND token = 'o/xXlFhyBO6NcKhllAGbZEpJFAuXbiIUWwLCJmH+Jok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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