SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e2dc1504fab82d5f4fa6a25cccce55fdd1180020cfaebbae17b7dfcecc7fa08' 
  AND token = '5bMK3oTTLS3uBtBJeT27xjg1qCjlOIbuBjxX+dg4vBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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