SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1246e0ec9b5d4b625f2b9e121dc719904fc1c61084b9c694cba0db131ec7643f' 
  AND token = 'lD0GnM4+ukc3h8FmQv4UypKPZG+5RsxQnnwiL5ckbKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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