SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c0ff5928f333dfbf922ae23aad0d2630f0adb35549b0c4a261755e21db3eeb2' 
  AND token = 'GvOJ1x1YAJV9lFHI3MuzK82hxyAcs/zT+iowYDrjkH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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