SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e0fb04cab0398449735cf9db2993dac0c6702a765afa925bd6df866a73eb51a' 
  AND token = 'i4CSuSp9rNBgjtkMdDbvhsrJgSgq628AlIiIds92Txc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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