SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79f4da2b41c5fbe9d8a7c53e0aae69491be9bf8d781907b2dce9ee12463ea73' 
  AND token = '/hOdBEHXVo0GADnt4+rVRfcIJ6h1ThezKb5s8z/CvPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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