SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bdf027e1ea81a7962fbbf52785887728cc0d0fc57da2d2192575062b43bb02c' 
  AND token = 'LG4WjdKAGlo2D2RgAcwJljVbnSB9MvLuGG+6Hjxr1hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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