SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aecc8eacd5b709d6637b50fb81858162371041d2aa29b722025bd0c813683017' 
  AND token = 'GAGvtDL0jRlgTdHftrIrDdbY8plhRYJWVRm6tTEGXJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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