SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9de63f275da3ca7053345e325e80eae4ea0994c34d19e6ee543d8cac88f4bac' 
  AND token = 'G5Z/dNjRNhOBco5jaxwLoP0g8WZrkCPVj5xAasBRfxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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