SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b66e72bfc1222d8aa9d827216dc36c1650b937038dc6c02cc4ef7e407a52718' 
  AND token = 'v6RiRYpeaPaqETR4jt8TI6fUzdhxEVgTJT5nEnIXrxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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