SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01dc10230c29330dad8f5cb1932ccd33edc5c69713db46e28a8587eefff759d3' 
  AND token = '37PBeip1giV37DaYbYvi9rWZcKyFVgApyxEWorZB4Yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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