SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '188d32e7d781ebb90fed9685508409d1fd7ce4fa2212cccd0f5733c9697d48ab' 
  AND token = 'CwKSdQw+Wbz7g4utIVr5Y5ruJR5R84mXy3P5Yaz2aqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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