SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c444efb2a8600fd45f6ca8d4e0786424ca0a5cfdee05aff29e4cdd57802a143' 
  AND token = 'maFjYhO1USk83F8rhTCT3E40ORGblg+5/7VKXQrSjpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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