SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eb6cbe020824eb083d29a885ce4fe8b4293407cb783e400d0996302f0e303412' 
  AND token = 'T5VRAV0nWryY7HZIK4hMaIWis4qykQ7uyndHkaTDYrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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