SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce768284d71e2cf1d369b44b64885fad49bc3da302efb7209eb07dd47e685268' 
  AND token = 'wJ4z7SWJE4LZu9U5xBwCXInBpiDuIHFEI/f+Bq3uVGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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