SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '41c12f541e033f7c6f87444b76d7a8eda79c296c4e6ab7318e1f34918a7810ff' 
  AND token = 'CThH8IU+3vk/GbjWavzqcVKUFwnwleuXYGVOSVNsAow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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