SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a2eab0602f603c1b95c146e57160a20c926a99bcaf676c9ce94d09c7632e767' 
  AND token = 'hI9vNTpt5muEKdGu/M457s36RvXbcNe/nd3wbrLnKRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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