SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dfcfb4f0752f81a5972c7bca50ba62601a581c0aeeaf04d0729fdec1d95352b3' 
  AND token = 'aCQ3vanfyDGezaWZT9ULwlnkZhB4ohSB9IaY2lS9dxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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