SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5471524e35e627a09c1f49722922a769b8c8d64cb7fa2d71809c0ac20e28178a' 
  AND token = 'M+iVGONuKJ7Wi12JjSJhFlZXLtfFXihuYaa/zhKJe58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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