SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d8b102b4d088df743616a449e31aba5e9688b0deb8245735aa7152d39570891' 
  AND token = 'p8KXxxMhqhj/G5S+myKNnhWPvLvhf/u+LKCsXQLX3+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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