SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c35db8d0af08792c2ea4e9bfa859658b7603be6d24d464c964e296df15519998' 
  AND token = 'sYOqdPttvcwrW1ah/c+jy1yRqt4ncldeIEwdAzf5aL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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