SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61759bcb270ab67adaa238b55b7c181878d9b5613f5dce2a669c5f4a91bcda8a' 
  AND token = 'KuLBsgNc35D7nB7f3yFUbuu9Msw5Nl6dW3GssF89HkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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