SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3b504859832d555d7f63680544d45bb257d47b0cb563f2478b6cfd04c21c0b' 
  AND token = 'F8qnxqCMNBVayX4+PN+40OQj0ggOY2p0QTZxvy00ZVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}