SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5039f0c532a1e0c2df27f152c61a2d87492276e9598cf0571703d37db0f15167' 
  AND token = 'rx9lq1WX8wpVW4xBgLqeOiDfEcJ/Hdp8NOBJ2IYwSis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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