SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '15fa02ffc211bc8f188572e33e5bb4aba7b8f624b390df053f485a10b6ecf983' 
  AND token = 'FkgT3zcXMNPLlLwhrrIV9Wh8GSMBDq7t2oHSQmIswsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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