SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9578283df98f3757c04cd2b13d5b7df6ac84e528d1e912cef5829b89b6099480' 
  AND token = 'mH30VJm55hMENvDVQrsesFPL9FCAtXhvSeQd8BUNfAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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