SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6315de2ec170dd61ce16ee80eb2c84d649f5e42085513df3f0815aaaffbfa321' 
  AND token = '3bwU4JHNFYIGfbOx+WM8Gq0ngc2Wx4Vx4Qjmo7AiNEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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