SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '291cf3a47688a26f057c6ca666d3c97528b60310d04a5c890fef2187fdb99cea' 
  AND token = '7myNn8CBoF93tONR+LqDey2pwGfR3GjwGK1ho9m/ppg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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