SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '832633dea691207d27347f9fcbdeb9789b89a0a5729a5c8d3f34a4c32b0f5592' 
  AND token = 'LVmSXYH7xpdvKfFckqRDNEw7Vj7y2YVpHtvM1JKywao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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