SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f7ae7ada437cd5fb4cfb54f178d44c13ff104389e291898c72af5a5b5c281f' 
  AND token = 'XWIbcWQkbyEHdHSuY+j4ikTXw2gqkgvX7tI2JymiOWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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