SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2feddf18f664138f3dcd979b2e0dfe062668325749798ab2f942b4c5081538f6' 
  AND token = 'Mz7zHaC932W9AfV5ZI4gAdGRsPsqVBgp1kkGgHzddWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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