SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3516e8d4e142e44ee4c673b2570b35352a43a7750ac982db8b971e2a292710ca' 
  AND token = 'tL6MlDMzL+e/RuDwFjybd5Q3Znr2okGLwGHxaIQFuiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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