SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cff9f5f0c4e8d580a39e218b4e74f35420d69f0463bfd88b12f923cebde4e9a1' 
  AND token = 'Lq7F4NdBFahyCiKMP+Gozn3WxswwHXs8Fal+ebCHB5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}