SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a705a1e945631c2eed83431bc91fd9d46a55bdadb9a89667e61891304543ee3' 
  AND token = 'RIWtUk+yKMkuVWW+K8p79mxziJWM8psWqxmzODz97BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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