SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ab4f35634156a51cf4ed3d4121f947c4b31a281445bc5bd558058dc74dc917f' 
  AND token = 'qY8Z8kOqVjtf/GXmjVQUiN5mD3GU9AS9PMCS7zM7fg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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