SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f3596ba431d479d7129763bc3e56c4324edaef3f99a4ae8b4d7e938933f9596' 
  AND token = '8xevVWtuMUMgBPpLlYVHuTJ5JKAvqCuMxtWasayNPXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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