SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e7dc683f21b3484918e4c630a9ffd5aac6dbac576b377897dfc8c50bd58cdb9' 
  AND token = 'LWpVwKM7D+N/U1H6KcJv1Nxm+YbtDdBnRvZsr3/d298=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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