SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '564c6813f518b15c154e8f6f2c84388af2155ad8907a453da821c3ebe266b319' 
  AND token = 'uD28NwqxfIzTa+7hFnALaFLLuYvFN+2bjupqTsdoOn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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